Vinylidene chloride interpolymers are well-known for their excellent barrier to mass transport of atmospheric gases and moisture vapor. These interpolymers have limited areas of application, however, because of poor melt processing characteristics. In particular, vinylidene chloride interpolymers in a melt plasticized state have poor heat stability and low melt strength. These same interpolymers, when fabricated, tend to be brittle and have low impact strength.
Similarly, polyvinylchloride (PVC) is well-known for its excellent physical properties. Specifically, PVC is easy to mold, inexpensive and inherently flame-retardant. Unfortunately, PVC resins provide a relatively low degree of barrier to mass transport of atmospheric gases and water vapor when compared to vinylidene chloride interpolymers. Moreover, despite the similar molecular structure of polyvinylidene chloride and PVC, a blend of the two resins is friable due to the lack of adhesion of the respective interfaces.
It is desirable to produce a polymeric composition possessing the desirable properties of both a vinylidene chloride interpolymer and PVC. It is to this goal that the present invention is directed.